Background: Despite initiatives to end Veteran homelessness, over 137,000 Veterans were homeless at some point during 2013. Homeless persons, compared to housed, are sicker and have mortality rates 5-9 times higher. Healthcare for homeless Veterans is characterized by discontinuities in care, difficulty adhering to treatment, and frequent use of emergency and inpatient care. Hepatitis C virus (HCV) is an exemplar condition for understanding deficiencies in health systems' care for homeless persons because of the high prevalence in this population (over 20%) and the need for continuity of care in both primary and specialty care. HCV is the most common blood borne disease in the US with 3.2 million persons infected. It causes liver damage, hepatocellular cancer, and death. Quality HCV care involves sequential steps from identification, to linkage to a specialist, treatment initiation and treatment completion. This pathway has been formalized in a model called the HCV Care Continuum. Among those infected with HCV, however, only 50% have been diagnosed, 38% referred to HCV specialty care, 11% put on anti-viral therapy, and 6% achieved sustained viral response (SVR; i.e. cure). Data suggest the percentages for homeless persons are lower. Objectives: The goal of this study is to provide the first system-wide analysis of health care for homeless Veterans, through the lens of HCV care; and then to develop an intervention to spread best practices for homeless HCV care throughout VHA. The aims are: Aim 1: Describe how homeless HCV+ Veterans are distributed among VA medical centers; Aim 2: Evaluate quality of care for homeless and non-homeless Veterans as measured by progress along the HCV Care Continuum and the relationship of quality to patient, facility, and housing characteristics. Aim 3: Develop an intervention to improve HCV care for homeless Veterans, and submit a proposal to pilot test the intervention. Methods: This is a 3-year mixed-methods study combining retrospective cohort analysis of VA databases with qualitative data collection. For quantitative analyses the study population consists of >6.5 million Veterans in VHA care between FY09-14. Two subsets are also analyzed: all homeless Veterans (around 267,000), and HCV+ Veterans who are homeless (around 36,000). Adjusted models will indicate whether degree of homelessness (long-term supportive housing, at-risk of homelessness, or currently homeless) and individual modifiable factors (e.g. PTSD, substance use) and facility characteristics have differential effects on achievement of Continuum measures. In Aim 3, based on the analyses of the 36,000 homeless HCV Veterans in VHA care, we will identify 3 higher and 3 lower performing facilities (on the Care Continuum) based on risk adjusted profiling. We will make site visits and interview stakeholders (e.g. clinicians, staff, Veterans) to learn about best practices, as well as challenge and barriers to providing HCV care to homeless Veterans in their facilities. Findings from qualitative and quantitative data will be incorporated into the design of an intervention. Anticipated impact on Veterans' healthcare: VHA supports efforts to end Veteran homelessness by 2015. Yet it has never assessed system-wide performance to ensure that healthcare for homeless Veterans is accessible, continuous, and engages Veterans in self-management of medical conditions. Such an analysis, using HCV as an exemplar condition, will be conducted in this study. It will identify strengths and weaknesses of VHA hepatitis care for homeless Veterans, pinpointing where breakdowns occur in the treatment pathway. It will also identify several high- and low-performing VA medical centers based on percentage of their HCV+ Veterans who initiated treatment. These sites will be visited to identify best practices and strategies for overcoming barriers. An intervention will be developed to spread best practices through implementation research. These studies will lead to improved care for homeless and non-homeless HCV+ Veterans alike.